Pops and us have been living on the same property since August. We have a house in the front and he has a casita (small home) in the back. Not sure how much I dug into it here, but he has PSP, which is a rarer form of Parkinson's. He got to a point that he needed to enlist much more help, which basically left us with nursing home or living with us. My wife is a real estate finding extraordinaire and found this great place with the 2 houses and plenty of space.
The house/property we are selling is his former place about an hour away. In order to get the current house while dad and I both owned our houses we had to get a loan from someone who's more like a private investor (2.5% over market rate). By my calculations, between insurance, electricity, taxes, etc on his former residence and interest on our new loan, as one unit, we're losing about $2K per month. (Fun fact: 2.5% difference on our 30 year loan is a $600 difference in payment, purely interest)
Our house sold in a heartbeat, we used it to re-bolster our emergency fund, pay off my truck and buy a few things we've been needing/wanting and then squirrel away the rest to weather the god awful mortgage payment until his house sold.
With the sell of his house, he will dump all the proceeds into the loan (he owns the other house outright) and the wifey and I will refinance under a new rate and shorter term. This will get my dad away from any payment and the W and I expect we can refinance at 5-10 years to get it knocked out ASAP.